Pulmonary drug delivery systems have been used for decades to deliver medicaments for the treatment of respiratory disorders. The principle behind pulmonary drug delivery is aerosolization of drug compounds to be delivered to bronchioles and alveoli. Despite facing challenges like particle size optimization and degradation, a number of companies have developed technologies to deliver treatments for diabetes, migraine, osteoporosis and cancer.
The available delivery systems include metered dose inhalers (MDIs), dry powder inhalers (DPIs), and nebulizers. MDIs were among the first to be introduced in the United States in the mid 1950s. The HFA-based (pressurized) MDI was introduced in the United States in 1995. Although DPIs were introduced in the 1970s, their use has been limited due to the overwhelming dominance of MDIs. Nebulizers are generally used within hospital settings. Technological advances within the pulmonary drug delivery technologies markets are taking place in non-CFC-based MDIs, DPIs, and liquid-based inhalers (LBIs).
Many preclinical and clinical studies have demonstrated that pulmonary delivery of medicaments is an efficient method for the treatment of both respiratory and systemic diseases. The many advantages of pulmonary delivery are well recognized and include rapid onset, patient self-administration, reduced side-effects, ease of delivery by inhalation, and the elimination of needles.
Nevertheless, methods for the administration of most medicaments have not significantly deviated from delivery via the traditional intravenous/intramuscular and oral routes to include pulmonary delivery via inhalation. The use of pulmonary delivery has been limited mainly to the administration of medicaments for the treatment of asthma.
It has been reported that in order to deliver a powder directly into the lower respiratory regions the powder should generally have a particle size of less than 5 μm. Further, powders in the 5-10 μm range have been found not to penetrate as deeply and instead tend to stimulate the upper respiratory tract regions.
When manufacturing drug formulations for dry powder inhalers (DPIs), the medicament must first be milled to obtain an acceptable particle size for pulmonary delivery. This micronization step can cause problems during manufacture. For example, the heat produced during milling can cause degradation of the medicament. Additionally, metal can rub off some mills and contaminate the medicament. Furthermore, due to the small size of the particles, dry powder formulations tend to agglomerate, especially in the presence of moisture.
Agglomeration results in low flowability of the particles which diminishes the efficacy of the dry powder formulation. As a result, careful supervision is required during milling, blending, powder flow, filling and even administration to ensure that the dry powder aerosols are properly delivered.
Thus, there is a need for new methods to prepare aerosols for medicament delivery. The present disclosure describes in part a method for combining nicotine or other medicaments with a delivery enhancing compound in a gaseous stream to generate an aerosol for pulmonary delivery, without the need for excipients or other additives including solvents.